Rheomega was my own project where I explored how the SustainX (the startup that had just shut down) isothermal foam compression/expansion technology could be used in other applications and if there were viable businesses to build from the tech.
Isothermal Compression & Expansion – a thermodynamic unicorn
Understand that isothermal compression or expansion is a mythical beast, an unattainable ideal, a practically impossibility. In engineering, these isothermal processes are used for theoretical understanding, for comparison of a real process to an idealized maximum, and are understood to be a useful fantasy – like frictionless pulleys, wires with no resistance, or plumbing without pressure drops. An isothermal process is a thing that does not and cannot exist in the real world.
With the foam tech, we weren’t breaking any laws of physics, but we had found a real & practical way to achieve 98% isothermality: over a 13:1 pressure ratio, the temperature would only change by 20C whereas a traditional (adiabatic) process would change the temperature by 300C+. That extra temperature change is ultimately lost energy so isothermal tech could be a big deal for more efficient processes and machines.
Some tough years for venture capital clean energy tech
In 2016, I spent about 6 months researching & working on the various Rheomega isothermal foam concepts, but ultimately shelved the effort as:
1) the clean tech investment scene was still hurting
2) the foam IP (intellectual property, i.e. patents) situation was unclear as the SustainX IP was repossessed via liens from the lawyers when the business shut down
Open Science & Engineering
In the spirit of open science and engineering, I posted my private notes & research below. The 3 concepts are:
- Foam Turbine – electricity generation system. Turbines are generally used to generate electricity, and the foam can greatly reduce the energy cost of the most energy expensive turbine step, compression.
- Foam Engine – a waste heat recovery machine that produces electricity.
- Foam Compressor – a gas compressor that uses up to 30% less energy than traditional compressors.
Techno-Economic Analysis
Foam Turbine
A practice pitch deck as part of my course work with Wasabi Ventures Academy (a VC-led startup bootcamp)
This deck was a more in-depth, technical look at the Foam Turbine
Foam Engine
The simple poster:
A 2 pager:
The older (2014) development work:
For the Foam Engine thermodynamic design, I used the free & excellent tool, CoolProp, for calculating gas properties. With CoolProp in Excel, and later in Matlab, I solved the air-water heat transfer energy balance at every step of the calculation to predict the machine’s performance.
